The present invention relates to an auxiliary oil reservoir for self-propelled irrigation systems and especially to an auxiliary oil reservoir for the transmission gear box and wheel drive gear boxes of the irrigation system water conduit support towers.
Wheeled line irrigation systems are commonly used throughout the United States for irrigating agricultural lands. Generally, the wheeled line irrigation systems include a plurality of wheeled towers supporting a linear water conduit in a manner that the wheeled towers and water conduit can be moved through an agricultural field for changing the position of irrigation sprinklers coupled to the water conduit. One end of the water conduit is coupled to a water main or well and sprinkler heads are mounted in spaced alignment along the water conduit between the wheeled towers. The irrigation system may be moved in an agricultural field by a motor coupled through a gear box to the wheels of the towers.
One type of wheeled line irrigation system in common use is a center pivot irrigation system used in the irrigation of large fields. These typically comprise a linear water conduit which is pivotally connected at one end to a source of water under pressure. The water conduit is carried in an elevated position by a plurality of spaced wheeled towers which are powered by hydraulic, pneumatic or electric motors to rotatably sweep the central conduit over a central pattern in a field. The central conduit includes a plurality of water sprinkling heads spaced over its length for distributing a spray of water on the circular field area as the center pivot irrigation conduit passes thereby. The center pivot and other wheeled line irrigation systems have been successful for uniform distribution of water over a field crop.
In the typical wheeled line irrigation system, the wheels are powered by a hydraulic, pneumatic, or electrical motor which drive a transmission which includes reduction gears in a sealed casing or box which is typically filled with oil. The gear box has one or more rotary shafts extending therefrom to the wheels through wheel drive gears encased in a wheel gear housing which is also filled with oil and changes the rotary shaft direction of power to drive right angle wheel axles to rotate the wheels. This type of system has worked successfully throughout the United States but, in a typical system, the sealed transmission housing and wheel gear housing will sometimes loose the oil through the seals since the gear housings are working in an adverse environment below sprinklers and adjacent the earth. If the seal fails or the oil leaks out of the transmission or wheeled gear housing, then the gears will lack lubrication which results in increased friction, heat, and failure of the drive system.
The present invention is directed towards an auxiliary oil reservoir placed in a position above the transmission and wheeled gear housings to provide oil under pressure to all of the sealed oil containing housings. This allows the oil in a sealed housing to expand and contract through the oil lines to the auxiliary oil reservoir to avoid a positive or negative pressure within the transmission housing. The auxiliary oil reservoir is also formed with a transparent tube which allows a quick visual inspection of the oil level for all the gear housings simultaneously.
Prior art patents which include lubricators for irrigation systems or the like can be seen in the Newcomb U.S. Pat. No. 4,280,591, for a wheeled line chain lubricator which includes an oil reservoir for a partially submerged sprocket wheel. The sprocket wheel is loosely carried on a stationary axle mounted within the reservoir to permit both rotation and lateral slidable movement. The teeth of the sprocket then urges oil into the links and rollers of the drive chain as it is moved over the rotating sprocket. In the Allen, Jr. U.S. Pat. No. 3,762,643, an irrigating apparatus includes a water conduit supported above crop height on a self-propelled movable support tower which support towers have a motor and transmission means to drive a movable base. A rigid enclosure is provided for the transmission to hold a reservoir lubricant in contact with the transmission to prevent leaves, sand, dirt, and foliage from the crop from coming into contact with and fouling the transmission. In the Dooley et al. U.S. Pat. No. 3,463,267, an oil impregnating method and apparatus for a chain is provided while in the Francois et al. U.S. Pat. No. 5,121,815, an emergency lubricating device for a main gear box of a rotary wing aircraft for lubricating the rotary wing aircraft gear box.
In contrast, the present invention is for an auxiliary oil reservoir which is added to an existing water conduit support towers to help avoid the transmission and gear boxes from being damaged from the loss of oil through seals which may have been damaged from sand, dirt, and moisture from an agricultural field and prevents the build-up of undue pressure within a gear box when the oil in the gear box becomes heated.